See, in my mind, the characters are part of their canon (and I include the comics in canon). To me, fanfic that resurrects a character only lasts as long as I'm reading the story. After it's finished, I return to the norm of "Spike's dead and I mourn and my heart aches." I still mourn Cordy and Wes and Fred and Lilah. It doesn't matter if I'm reading a fic where they're alive and well. My knowledge of them is that they're dead and they're not coming back from that. It's one thing to know someone will die eventually because they're mortal. It's another to know exactly how they died - that makes it real. And in fiction, the reality of their death always casts a shadow on them for me.

I imagine it's similar to how people feel reading fic about Lorne. Andy Hallett's death affects the piece.

But then, this is partially about me. When I love characters, I love them. Their deaths are real to me and I really do grieve for them. So yeah, there's no coming back from death for me when it's in canon. Unless there's a resurrection.